Determine the positivenes or negativeness of a generic statement

I want to know if a twit is positive or negative. For example:

thesis: jonas brothers eat charcoal "Jonas Brothers are going to eat charcoal" >>> Positive

"Jonas Brothers have nothing to do with charcoal" >>> Negative

thesis: melmac is destroyed "Melmac is dead" >>> positive

"Alf is living with his friends in melmac" >>> negative

I want to know if there's some kind of algorithm to do this, on a 开发者_如何学Gogeneric, non languaje specific basis.

What's the easiest approach? Thanks in advance.

I think I good approach would be to keep a dictionary of negation statements : don't, isn't, nothing, etc. Find those keywords in a statement. You would also have to account for double negatives through a counting system. For instance " I haven't not given an answer", is positive but contains negative words.